Food recalls and warnings happen every day. But the latest warning from the Food and Drug Administration about frozen shrimp is an odd one. That’s because the health agency is concerned about possible radioactive contamination.

The FDA issued an alert on Tuesday for some Great Value brand frozen raw shrimp sold at Walmart. The shrimp was processed by PT. Bahari Makmur Sejati of Indonesia, also known as BMS Foods, and flagged by Customs and Border Protection at four different ports of entry.

The FDA explains that it hasn’t found shrimp on store shelves that have tested positive for radioactive contamination, but is concerned the food “may have become contaminated with Cs-137” because it “appears to have been prepared, packed, or held under insanitary conditions.” The FDA reportedly found Cs-137 in a single shipment of shrimp that obviously wasn’t allowed to be sent to stores.

The amount of Cs-137 found in the shrimp was 68 Bq/kg, which is below the standard for federal intervention, which sits at 1200 Bq/kg. Cs-137 is a radioisotope of cesium that is not naturally occurring and comes from nuclear explosions that started to contaminate Earth’s atmosphere since the first tests of 1945.

Trace amounts of Cs-137 can now be found in the environment, and the FDA explained in its alert that it was concerned about the kind of exposure the shrimp had while being prepared and packaged.

The shrimp lots that are being recalled:

• Great Value brand frozen raw shrimp, lot code: 8005540-1, Best by Date: 3/15/2027
• Great Value brand frozen raw shrimp, lot code: 8005538-1, Best by Date: 3/15/2027
• Great Value brand frozen raw shrimp, lot code: 8005539-1, Best by Date: 3/15/2027

Consumers are being told to dispose of any shrimp they find with those lot codes.

“FDA has also added PT. Bahari Makmur Sejati to a new import alert for chemical contamination to stop products from this firm from coming into the U.S. until the firm has resolved the conditions that gave rise to the appearance of the violation,” the health agency said.

The U.S. shrimp industry has long complained about foreign shrimp undercutting prices for the domestic product, and the Southern Shrimp Alliance has been highlighting what it calls “disturbing reasons” the FDA must crack down on shrimp imported from Indonesia. The group pointed to a health alert from Aug. 14 over concerns about unsanitary conditions.

The Southern Shrimp Alliance has welcomed President Donald Trump’s tariffs on shrimp from Asia, which are pretty much guaranteed to raise prices for consumers but will give local shrimpers a better shot at staying competitive. Trump has threatened a 50% tariff on India, which is likely to drive many shrimp companies in that country to either go out of business or look for other markets. India already faces a 25% tariff, and another 25% is scheduled to be tacked on Aug. 27 to hurt the country over its purchase of Russian oil, according to Reuters.

BMS didn’t immediately respond to a request for comment on Tuesday. Gizmodo will update this article if we hear back.